The turnover of O-alkyl lipids will be measured in the plasma membranes of Ehrlich ascites tumor cells. The ether lipid content of the plasma membranes of chronic lymphocytic leukemia cells will be compared with that of normal lymphocytes. After completion of these two studies, we will begin measurements of the O-alkyl and alk-1-enyl lipid contents of plasma membranes from spontaneously metastasizing and non-metastasizing mammary tumors. Kim et al. (Proceedings National Academy of Science, 72:1012, 1975) have presented data on immunologic escape mechanisms in spontaneously metastasizing and non-metastasizing tumors. In their paper they describe methods used to isolate and characterize plasma membranes from the tumors which they evaluated. We plan to evaluate the relationship between the metastasizing capacity and ether lipid content of mammary carcinomas. The results will be compared with non-metastatizing carcinomas. We are currently in the process of evaluating whether or not the hydrogen loss which takes place between acyl DHAP and O-alkyl DHAP depends on the presence of hexadecanol. If the loss is hexadecanol dependent it may be possible to postulate a mechanism. If the hydrogen exchange is not hexadeconal dependent an intermediate compound will be sought. BIBLIOGRAPHIC REFERENCES: Friedberg. S.J. and J.A. Reynolds. The molar ratio of the two major polypeptide components of human high density lipoprotein. J. Biol. Chem. 251:4005-4009 (1976). Friedberg, S.J. Plasma transport forms of ingested fatty alcohols in the rat. Lipids. 11:587-593 (1976).